docs: def update_nodes(self, char, patch, backdate=False):
          """Change the stats of nodes in a character according to a
          dictionary.
  
          """
          if backdate:
              parbranch, parrev = self._real._parentbranch_rev.get(
                  self._real.branch, ('trunk', 0)
              )
              tick_now = self._real.tick
              self._real.tick = parrev
          for i, (n, npatch) in enumerate(patch.items(), 1):
              self.update_node(char, n, npatch)
          if backdate:
              self._real.tick = tick_now